After the news that Facebook Credits would become mandatory in five months was broken yesterday, Facebook head of product marketing Deb Liu addressed developer concerns today at the Inside Social Apps conference.

When moderator Eric Eldon alluded to fears that mandatory Facebook Credits would put some developers out of business, Liu said, “Every single day we know developers get to choose between our platforms and another platform” a statement which was met with laughter from the audience, as Facebook is the most dominante player in the space and for some the only option for such large scale distribution. Liu recomposed “We want to make Facebook the most attractive place to invest, and keep users with credits in their pockets.”

Liu went on to focus on the incentives to developers for using Facebook Credits, including emphasizing Facebook’s promotion of games that used Credits as their sole payment, frictionless payments and the new “Buy With Friends” feature which allows a developer to set up a feature that allows users to share purchases within games and then friends can then buy those items at a discount.

When asked at the end of the panel if the Credits-only decision would be poisonous to “whales” or users who spend extreme amounts of money in-game, Liu said it was a legitimate concern and system improvements would have to be made on a case by case basis.